68 



a. Lyclel-her — On Fossil Mammalia. 



regularly outwards from their roots. The frontals seem to have 

 been flat, without any depression at the junction with the nasals ; 

 and the premaxillte extend upwards to articulate with the frontals. 

 The form of the palate is very like that of C. commune ; but the 

 interval between m. 1 and the incisors is much less, and the incisors 

 and canine are considerably larger. 



In Fig. 4 there is represented the left ramus of the mandible, im- 

 perfect posteriorly, of a Cceno- 

 therium, from Caylux, which 

 from its size and general charac- 

 rm///--^-^ ters may very probably be re- 

 ' w J^ ferred to the same species as the 

 cranium just described. It is 

 of considerably smaller size than 

 the mandible of C. FilhoJi, but 

 agrees in having a distinct dias- 

 tema between pm. 1 and pm. 2. 

 Fig. 4. Ccenothermm, sp. The left Jt is much larger than the man- 

 ramus of the mandible imperfect pos- ^-^^^^ ^^ ^_ quinquedentatim and 

 teriorly : from the Upper Jiocene oi ., ., -^ , ^ . , , 



Caylux. 1. (B.M. No. M. 1401,a.) <^ • gracde; and is also larger 



than that of C. cadurcense, in 

 which the length of the space occupied bj'^ the last six cheek-teeth is 

 only 0-0215. 



The following are the dimensions of the cranium and mandible. 



Cranium. — Length of series of cheek-teeth 0-028 



,, ,, true molars 0'013 



Greatest width of nasals (anteriorly) 0-0052 



Vertical diameter of orbit -0 1 25 



Length of diastema 0-002 



Mandible.— 'MiXiiem.e length 0-044 



height 0-027 



Length of dental series 0-033 



last six teeth 0-0248 



Height at pm. 2 0-0065 



,, m. 3 0-083 



Length of diastema 0-0021 



From the foregoing comparisons it is quite evident that the cranium 

 mentioned above is specifically distinct from C. FilhoJi ; and it cannot 

 be identified with Mouillactlierium (from which it is distinguished 

 by the two structural characters noted in the case of C. Filholi) ; or with 

 the so-called C. Courtoisi, or C. collotarsmii. It differs from all the seven 

 species of Ccenotherium recognized by Dr. Filhol from the Couriion, 

 St. Gerand-le-Puy, and Quercy beds ; but its resemblance to C. 

 commune is sufficiently close to suggest the question whether it 

 might not be the male form of that species. Against this view 

 there is, in the first place, the circumstance that the palate is shorter 

 than in C. commune ; and in the second place, that among the very 

 numerous crania of that species from Cournon none present the 

 characters of the present form ; but are all (where the teeth are 

 fully developed) characterized by the total absence of a diastema in 

 both jaws. 



The case of the two varieties of C. gracile noticed above indicates, 



